Is It Possible to Predict the Failure of Noninvasive Mechanical Ventilation for Acute Respiratory Failure Due to Pneumonia?

Abstract

Purpose: Non-invasive mechanical ventilation (NIMV) treatment in patients with acute hypoxemic respiratory failure due to pneumonia are controversial. The aim of this study is to determine the prognosis, failure rate of NIMV and risk factors for intubation in these patients. Methods: Patients who were treated with NIMV for acute respiratory failure due to pneumonia in our intensive care unit (ICU) were assessed retrospectively. Demographic, clinical characteristics and laboratory results of patients were recorded. Results: Eighty four patients (29 female, age 67 years, APACHE II score 17.5+/-7.0, median PaO2/FiO2 rate 222) were included in this study. NIMV was started on the first day after admission to ICU. The acute respiratory failure develpoed due to community, hospital acquired, healthcare associated pneumonia and pneumonia in immunocompromised patients (29.8%, 22.6%, 16.7%, 29.8%, respectively). 59.5% of patients were intubated on the second day because of failure of NIMV. In the patients of of whom the NIV failed, the baseline APACHE II score, respiratory rate and EPAP level were higher (p=0.008,p=0.001,p=0.002, respectively) and PaO2/FiO2 rate, hemoglobine, albumin levels were lower (p=0.001,p=0.001,p=0.001, respectively). The mortality rate due to acute respiratory failure was 58.3%. Hemoglobine level of <10 g/dl, existence of ARDS, absence of COPD and administration of vasopressor treatment were found to be independent risk factors for failure of NIMV (OR values were 11.09, 5.61, 6.17, 33.93 respectively) . Conclusions: NIMV can be applied to the patients who have acute hypoxemic respiratory failure due to pneumonia. However, there is a probability of failure of NIMV due to anemia, development of ARDS and baseline requirement for vasopressor treatment at baseline. Clinical Implications: NIMV can be used for the treatment of acute hypoxemic respiratory failure due to pneumonia. On the other hand, some factors such as aneima, existence of ARDS and vasopressor treatment at baseline may cause the failure of NIMV. Therefore, while applying NIMV in this group of patients, they should be monitored carefully.